Lipases (EC 3.1.1.3), which can be defined as carboxylesterases which catalyze the hydrolysis of acylglycerols, are physiologically very important enzymes as one of the three major digestive enzymes together with amylases and proteases. They hydrolyse lipids to glycerol and fatty acids, but can also function in esterification or transesterification reactions.
Lipases have applications in several industrial processes such as processing of oils and fats, detergent manufacturing, paper processing and in the cheese making and baking industries.
WO 98/45453 discloses a lipolytic enzyme (and variants thereof) derived from the filamentous fungus Aspergillus tubingensis. This enzyme is sometimes referred to as “lipase 3”. WO 98/45453 characterizes several of the physicochemical characteristics of lipase 3. Uses of this lipolytic enzyme for improving the properties of bread were also described, in particular for improving the properties of bread.
WO 98/45453 also described the cloning and expression of lipase 3 and its variants in Aspergillus tubingensis. It was found that this lipolytic enzyme could be overexpressed in Aspergillus tubingensis, however the enzyme was overglycosylated in A. tubingensis which, in some situations, can decrease its activity.
There is a need for a method for the production of lipase 3 and its variants and other lipolytic enzymes on a commercial scale and using expression hosts which provide high levels of protein expression and yield. In addition, there is also a need to overcome the problem of decreased enzyme activity due to overglycosylation of the lipolytic enzyme as seen for example when it is overexpressed in A. tubingensis. 